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Non-visualisation of cavum septi pellucidi: implication in prenatal diagnosis?

Hosseinzadeh K, Luo J, Borhani A, Hill L - Insights Imaging (2013)

Bottom Line: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal.Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Presbyterian South Tower, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite 3950, Pittsburgh, PA, 15213, USA, hosseinzadehk@upmc.edu.

ABSTRACT

Objective: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.

Background: Observation of a normal cavum septi pellucidi (CSP) is an important landmark in the second and third trimester prenatal ultrasound evaluation of the fetal brain, and its visualisation provides reassurance of normal central forebrain development. Non-visualisation of the CSP is a prenatal sonographic finding, which in most cases is associated with neuroanatomical anomalies that include agenesis of the corpus callosum, schizencephaly, septo-optic dysplasia, holoprosencephaly, chronic hydrocephalus and acquired fetal brain injury. Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal. Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP. When non-visualisation of the CSP is suspected, magnetic resonance imaging (MRI) of the fetal brain can confirm and evaluate associated anomalies.

Conclusion: Visualisation of the CSP is an integral component of the prenatal ultrasound and its non-visualisation is associated with other malformations, diagnosis of which is aided by MRI.

Teaching points: • Cavum septi pellucidi (CSP) is an important landmark in the prenatal ultrasound evaluation of the fetal brain, and is a marker for normal central forebrain development. • Non-visualisation of the CSP is most commonly associated with other neuroanatomical abnormalities. • Examination of the fetal brain by MRI can confirm the sonographic findings and evaluate for associated anomalies.

No MeSH data available.


Related in: MedlinePlus

Open-lip schizencephaly. a Coronal ultrasound through the atria at 30 weeks’ gestation with non-visualisation of the CSP (not shown) demonstrates a supratentorial cyst (asterisk), with a differential diagnosis of porencephaly versus schizencephaly. b Coronal T2-weighted MRI at 32 weeks’ gestation demonstrates absence of the CSP and bilateral frontoparietal clefts lined by grey matter (arrow) extending from the pial surface to the lateral ventricle consistent with open-lip schizencephaly
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Fig3: Open-lip schizencephaly. a Coronal ultrasound through the atria at 30 weeks’ gestation with non-visualisation of the CSP (not shown) demonstrates a supratentorial cyst (asterisk), with a differential diagnosis of porencephaly versus schizencephaly. b Coronal T2-weighted MRI at 32 weeks’ gestation demonstrates absence of the CSP and bilateral frontoparietal clefts lined by grey matter (arrow) extending from the pial surface to the lateral ventricle consistent with open-lip schizencephaly

Mentions: This is a rare CNS malformation involving the grey matter, characterised by a cleft lined by grey matter extending from the pial surface to the lateral ventricle [16]. Schizencephaly has an incidence of 1.5 in 100,000 live births [17]. The aetiology is thought to be a disruption of gray matter migration in early embryogenesis. Non-visualisation of the CSP is an imaging finding in two-thirds of schizencephaly cases and is usually associated with fronto-parietal clefts. Other imaging findings include ACC, polymicrogyria and heterotopia [16, 18]. There are two types of schizencephaly. Type I is the closed-lip form, in which the edge of the cleft is fused. Type II is the open-lip form, in which the cleft extends from the ventricle to the surface of the brain and the edge of the cleft is not fused (Fig. 3) [19]. In a recent large survey of a regional register in the United Kingdom, 33 % of antenatally diagnosed cases of schizencephaly were established by fetal MRI only, an important modality in the evaluation of the cleft lining and sulcation pattern. Additionally, the majority of cases were identified after 22 weeks gestational age. Depending on the size and appearance of the cleft, diagnosis of schizencephaly may be difficult during screening ultrasound and, when visualised, may not be confidently differentiated from HPE or porencephaly (intracerebral cavitation secondary to haemorrhage and ischaemia) [17]. Distinguishing these entities is important given their differing prognosis.Fig. 3


Non-visualisation of cavum septi pellucidi: implication in prenatal diagnosis?

Hosseinzadeh K, Luo J, Borhani A, Hill L - Insights Imaging (2013)

Open-lip schizencephaly. a Coronal ultrasound through the atria at 30 weeks’ gestation with non-visualisation of the CSP (not shown) demonstrates a supratentorial cyst (asterisk), with a differential diagnosis of porencephaly versus schizencephaly. b Coronal T2-weighted MRI at 32 weeks’ gestation demonstrates absence of the CSP and bilateral frontoparietal clefts lined by grey matter (arrow) extending from the pial surface to the lateral ventricle consistent with open-lip schizencephaly
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3675254&req=5

Fig3: Open-lip schizencephaly. a Coronal ultrasound through the atria at 30 weeks’ gestation with non-visualisation of the CSP (not shown) demonstrates a supratentorial cyst (asterisk), with a differential diagnosis of porencephaly versus schizencephaly. b Coronal T2-weighted MRI at 32 weeks’ gestation demonstrates absence of the CSP and bilateral frontoparietal clefts lined by grey matter (arrow) extending from the pial surface to the lateral ventricle consistent with open-lip schizencephaly
Mentions: This is a rare CNS malformation involving the grey matter, characterised by a cleft lined by grey matter extending from the pial surface to the lateral ventricle [16]. Schizencephaly has an incidence of 1.5 in 100,000 live births [17]. The aetiology is thought to be a disruption of gray matter migration in early embryogenesis. Non-visualisation of the CSP is an imaging finding in two-thirds of schizencephaly cases and is usually associated with fronto-parietal clefts. Other imaging findings include ACC, polymicrogyria and heterotopia [16, 18]. There are two types of schizencephaly. Type I is the closed-lip form, in which the edge of the cleft is fused. Type II is the open-lip form, in which the cleft extends from the ventricle to the surface of the brain and the edge of the cleft is not fused (Fig. 3) [19]. In a recent large survey of a regional register in the United Kingdom, 33 % of antenatally diagnosed cases of schizencephaly were established by fetal MRI only, an important modality in the evaluation of the cleft lining and sulcation pattern. Additionally, the majority of cases were identified after 22 weeks gestational age. Depending on the size and appearance of the cleft, diagnosis of schizencephaly may be difficult during screening ultrasound and, when visualised, may not be confidently differentiated from HPE or porencephaly (intracerebral cavitation secondary to haemorrhage and ischaemia) [17]. Distinguishing these entities is important given their differing prognosis.Fig. 3

Bottom Line: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal.Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Presbyterian South Tower, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite 3950, Pittsburgh, PA, 15213, USA, hosseinzadehk@upmc.edu.

ABSTRACT

Objective: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.

Background: Observation of a normal cavum septi pellucidi (CSP) is an important landmark in the second and third trimester prenatal ultrasound evaluation of the fetal brain, and its visualisation provides reassurance of normal central forebrain development. Non-visualisation of the CSP is a prenatal sonographic finding, which in most cases is associated with neuroanatomical anomalies that include agenesis of the corpus callosum, schizencephaly, septo-optic dysplasia, holoprosencephaly, chronic hydrocephalus and acquired fetal brain injury. Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal. Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP. When non-visualisation of the CSP is suspected, magnetic resonance imaging (MRI) of the fetal brain can confirm and evaluate associated anomalies.

Conclusion: Visualisation of the CSP is an integral component of the prenatal ultrasound and its non-visualisation is associated with other malformations, diagnosis of which is aided by MRI.

Teaching points: • Cavum septi pellucidi (CSP) is an important landmark in the prenatal ultrasound evaluation of the fetal brain, and is a marker for normal central forebrain development. • Non-visualisation of the CSP is most commonly associated with other neuroanatomical abnormalities. • Examination of the fetal brain by MRI can confirm the sonographic findings and evaluate for associated anomalies.

No MeSH data available.


Related in: MedlinePlus